Articles

Co-infection and Syndemics

Edited by:
Professor Pascale Allotey, Prof. Xiao-Nong Zhou

Poverty has been established as the driver for many diseases, both infectious and non-infectious. The major focus of research in prevention and management has taken a single disease focus. The increasing occurrence of multiple infections and diseases, however, cannot be ignored. Co-infection is the simultaneous infection of a host by multiple pathogen species, for instance multi-parasite infections. Co-infection also occurs as simultaneous infection of a single cell by two or more virus particles, which can arise incrementally by initial infection followed by superinfection. Co-infection is of particular human health importance because pathogen species can interact within the host. Interactions within the host can have either positive or negative effects on each of the co-infecting parasite species. Under positive parasite interactions, disease transmission and progression are enhanced. Syndemics refers to the aggregation of two or more diseases or afflictions in a population where there is a synergistic relationship which enhances and exacerbates the negative health effects of any or all of the diseases.

The notion of syndemics can be expanded further to situate the occurrence of multiple diseases within the context of poverty and other mitigating factors that support and perpetuate poor health. Syndemics tend to develop under conditions of health disparity, caused by poverty, stress, or structural violence, and contribute to a significant burden of disease in affected populations. Given that social conditions can contribute to the clustering, form and progression of disease at the individual and population level, it poses a great challenge in understanding the processes that generate these patterns of co-infection and syndemics.

In this special issue, we present a series of papers that explicitly address the importance of co-infection and syndemics in order to trigger more research on and a better understanding of how a suite of co-infections within or between host as well as syndemics among populations will respond to better medical and public health interventions.

This study assessed the prevalence of coinfection with malaria and intestinal parasites, as well as determine its association with anaemia among febrile children 10 years and below admitted to the Muyuka district hospital, Cameroon and found no significant association with anaemia despite the high prevalence of malaria, intestinal parasitic infections (IPIs), and malaria and IPIs coinfection. Image: Infected erythrocytes containing ring stages of Plasmodium falciparum.

This review summarises and discusses current information available and gaps in research on malaria co-infection with gastro-intestinal helminths and tissue-dwelling parasites with emphasis on helminthic infections, in terms of the effects of migrating larval stages and intra and extracellular localisations of protozoan parasites and helminths in organs, tissues, and vascular and lymphatic circulations. Image: Tissue-dwelling parasites.

Our study has identified the critical influence of traditional, cultural and supernatural beliefs in relation to seeking help from traditional sector providers for both leprosy and TB. Our paper concluded that socio-cultural concepts of illness causation and associated help seeking preferences rooted in distinct features of tribal culture need to be addressed to improve programme outcomes. Image: Bohada is a cultural festival of tribes in Thane District.

The change patterns of the cell profile of circulating lymphocytes were indentified in human co-infection of Mycobacterium tuberculosis and hookworm, which might indicate that the humoral and cellular immune responses are more suppressed. Image: The expressions of B and T cell subsets in different groups.

Pichia guilliermondii-Wuchereria bancrofti co-infection was recorded in a large number of microfilaraemic patients living in a filarial endemic zone of India. The fungus was identified and characterized by PCR-based molecular technique. Image: Pichia guilliermondii-Wuchereria bancrofti co-infection in microfilaraemic patients.

Each of the various strategies currently employed to face the burden of malaria and other vector-borne diseases in the tropics, is seriously inadequate. Despite enormous efforts, vaccines which represent the ideal weapon against these parasitic diseases are yet to be sufficiently developed and implemented. Chemotherapy and vector control are therefore the sole effective attempts to minimize the disease burden. Nowadays, both strategies are also highly challenged by the phenomenon of drug resistance, which affects virtually all drug regiments currently used. Image: Control of malaria and other vector-borne protozoan diseases.

Babesiosis caused by B. microti is emerging in the malaria endemic areas along the China-Myanmar border in the Yunnan province, P.R. China. which is ignored because of low parasitemia or mixed infection with Plasmodium. More sensitive and specific diagnosis methods are needed to response the emergency of babesiosis and malaria co-infection. Image: Morphology differences of ring-form stages of B. microti and Plasmodium.

We carried out a survey to study the immune status of an HIV-infected population, and the effect of co-infection of HIV and intestinal parasites on selected parameters of the human immune system. Co-infected with different intestinal parasites may cause various changes of the immune status and associated disparate consequence. Image: Blastocystis hominis cysts in the stool from HIV-infected individual.

Advances in antiparasitic chemotherapy have made combination chemotherapy a real possibility. As yet, the pathognomonic and subsequent treatment of protozoan and helminth concomitance in murine models is not well understood. This study evaluated the efficacy of combined chemotherapy using Pentostam and PZQ in BALB/c mice co-infected with L. major and S. mansoni. Image: Lesion size progression of L. major+S.mansoni co-infected mouse from control group at week 10.

The article is all about the impact of the diabetes mellitus on the progression and prevalence pulmonary tuberculosis and how this research finding can be utilised as relevant indicators to monitor pulmonary tuberculosis incidence in diabetic patients. Image: a picture showing the transmission of tuberculosis from an active case to healthy person.

The fishing communities of Africa remain at higher risk of acquiring both infections and co-infections. The available evidence indicates that immunological interactions of the two diseases in single human host are associated with severe morbidities. Image: Fishermen at Kayenze village, one of the fishing villages on the southern shore of the Lake Victoria, north-western Tanzania.

The article describes the impact of the integration of TB and HIV services on TB treatment outcomes, and how these outcomes can be utilised as relevant indicators to monitor the effectiveness of the integration. Image: A graph comparing number of TB patients dying, after integration of TB and HIV services, who are HIV-positive or negative.

To promote awareness of the importance of clonorchiasis, this Review examines the global epidemiology status and characteristics, as well as the relationship between Clonorchis sinensis infection and cholangiocarcinoma. Image: Raw freshwater fish causing clonorchiasis.